Fixing problem with new notifications system on upload 2 equal attachments.

taiga/projects/notifications/migrations/0003_auto_20141029_1143.py

@@ -0,0 +1,18 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('notifications', '0002_historychangenotification'),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name='historychangenotification',
+            unique_together=set([('key', 'owner', 'project', 'history_type')]),
+        ),
+    ]

taiga/projects/notifications/models.py

@@ -67,3 +67,6 @@ class HistoryChangeNotification(models.Model):
                                 verbose_name="project",related_name="+")
 
     history_type = models.SmallIntegerField(choices=HISTORY_TYPE_CHOICES)
+
+    class Meta:
+        unique_together = ("key", "owner", "project", "history_type")